I used to have one of those too. Mine was purchased from a gift shop on the east coast. Yours is in much nicer condition.
My most recent purchase! An interesting type. Made for the Duke of Northumberland, most sites will claim that only 2,000 of these were made for the duke to distribute in Dublin however it seems that the number more likely minted is closer to 100,000 as the royal mint is said to have produced £5,000 worth of shillings in 1763. I would agree with the larger number as well since despite every auction listing it as scarce and rare, it seems there's 2-3 available on the market at any given time. 5 that I know of when this one was auctioned off. These are really great pieces in hand because they are a bit like a small medallete with a relatively high relief portrait and flashy fields. Very few of these exist in below AU grades so it seems their survival rate is high and they were kept and not circulated as readily as other issues.